1. Field of the Invention
The present invention relates to mobile systems, and more particularly, to monitoring location of mobile units.
2. Background
Mobile telephones or units (cell phones) are used in every facet of modern day lives. Typically, a service area for a mobile telephone is divided into cells. Every cell includes a base station. Cells adjacent to a serving cell at any given time are referred to as neighboring cells.
Various wireless standards govern the operation of such units. For example, CDMA, GSM and TDMA are such standards, incorporated herein by reference in their entirety. These standards require every mobile unit to perform significant processing related to measuring a neighboring cell's signal strength. This requires a mobile unit to frequently turn on a RF transmitter within the mobile unit and consume power to send information to the serving network. This processing results in unnecessary power consumption even if a mobile unit is stationery or moves within a small area.
One solution for the foregoing problem is provided in U.S. Pat. No. 6,108,545, in which a user can input a time period when the mobile unit will be in a general area. The mobile unit then does not monitor the cells.
This solution is based on user input and hence its accuracy depends on the user's ability to predict when the mobile unit will be in the general area. Commercially, this solution is tedious and inaccurate.
Therefore, there is a need for a system that can automatically detect a mobile unit's location and/or movement, and stops monitoring the mobile unit's location resulting in power savings.